| Summary: | 博士 === 國立臺北科技大學 === 分子科學與工程系有機高分子博士班 === 107 === Orpinomyces sp. Y102 CelC7 (Orp CelC7) belongs to glycoside hydrolase family 6 (GH6), cleaves beta-1.4-glucosidic linkage of cellulose and relases cellobiose and cellotriose. The crystal structures of Orp CelC7 and cellobiose bound complex are solved at a resolution of 1.80 and 2.78 Å, respectively. Cellobiose occupies subsites +1 and +2 within the active site of Orp CelC7 and forms hydrogen bonds with two key residues of Asp248 and Asp409. The Orp CelC7 comprises two disulfide bonds, nine alpha-helices and seven beta-strands arranged to be a distorted α/β barrel topology (TIM barrel like). There are two major loops forming two substrate binding site conformations, one is short tunnel-like for cellobiohydrolase and the other is cleft for endoglucanase activity. In addition, LC-MS/MS analysis revealed that cellobiose (major) and cellotriose (minor) products of the endo- and exo- activity of the GH6 Orp CelC7, respectively.
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